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<A href="introduction6.htm">Debugging Tools for Windows (WinDbg, KD, CDB, NTSD)</A> &gt; <A href="debugger_reference.htm">Debugger Reference</A> &gt; <A href="debugger_commands.htm">Debugger Commands</A> &gt; <A href="kernel_mode_extensions.htm">Kernel-Mode Extension Commands</A> &gt; </div>
	<div id="winchm_template_title">!memusage</div>
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	<div id="winchm_template_content"><div id="mainSection"><p>The <b>!memusage</b> extension displays summary statistics about physical memory use.</p>
<p>Syntax</p>
<pre class="syntax"><b>!memusage </b>[<i>Flags</i>]</pre>
<h2><a id="ddk__memusage_dbg"></a><a id="DDK__MEMUSAGE_DBG"></a>Parameters</h2>
<p></p>
<dl>
<dt><a id="_______Flags______"></a><a id="_______flags______"></a><a id="_______FLAGS______"></a>       <i>Flags</i>      </dt>
<dd>
<p>  Can be any one of the following values. The default is 0x0.</p>
<p></p>
<dl>
<dt><a id="0x0"></a><a id="0X0"></a>0x0</dt>
<dd>
<p>Displays general summary information, along with a more detailed description of the pages in the PFN database. See the Remarks section for an example of this type of output. </p>
</dd>
<dt><a id="0x1"></a><a id="0X1"></a>0x1</dt>
<dd>
<p>Displays only summary information about the modified no-write pages in the PFN database..</p>
</dd>
<dt><a id="0x2"></a><a id="0X2"></a>0x2</dt>
<dd>
<p>Displays only detailed information about the modified no-write pages in the PFN database.</p>
</dd>
<dt><a id="0x8"></a><a id="0X8"></a>0x8</dt>
<dd>
<p>Displays only general summary information about memory use.</p>
</dd>
</dl>
</dd>
</dl>
<h3><a id="Environment"></a><a id="environment"></a><a id="ENVIRONMENT"></a>Environment</h3>
<table>
<tr>
<td>Modes</td>
<td>kernel mode only</td>
</tr>
</table>
<p> </p>
<h3><a id="DLL"></a><a id="dll"></a>DLL</h3>
<p>
          Kdexts.dll
         </p>
<h3><a id="Additional_Information"></a><a id="additional_information"></a><a id="ADDITIONAL_INFORMATION"></a>Additional Information</h3>
<p>Physical memory statistics are collected from the Memory Manager's page frame number (PFN) database table.</p>
<p>This command takes a long time to run, especially if the target computer is running in 64-bit mode, due to the greater amount of data to obtain. While it is loading the PFN database, a counter shows its progress. To speed up this loading, increase the COM port speed with the <a href="#Bookmark2211"><b>CTRL+A (Toggle Baud Rate)</b></a> key, or use the <a href="#Bookmark2065"><b>.cache (Set Cache Size)</b></a> command to increase the cache size (perhaps to around 10 MB).</p>
<p>The <b>!memusage</b> command can also be used while performing <a href="#Bookmark1261">local kernel debugging</a>.</p>
<p>Here is an example of the output from this extension:</p>
<pre class="syntax" xml:space="preserve"><code>kd&gt; !memusage
 loading PFN database
loading (98% complete)

Compiling memory usage data (100% Complete).
             Zeroed:     49 (   196 kb)
               Free:      5 (    20 kb)
            Standby:   5489 ( 21956 kb)
           Modified:    714 (  2856 kb)
    ModifiedNoWrite:      1 (     4 kb)
       Active/Valid:  10119 ( 40476 kb)
         Transition:      6 (    24 kb)
            Unknown:      0 (     0 kb)
              TOTAL:  16383 ( 65532 kb)

  Building kernel map
  Finished building kernel map
Scanning PFN database - (99% complete) 

  Usage Summary (in Kb):


Control Valid Standby Dirty Shared Locked PageTables  name

8251a258    12    108     0     0     0     0  mapped_file( cscui.dll )
827ab1b8     8   1708     0     0     0     0  mapped_file( $Mft )
8263c408   908     48     0     0     0     0  mapped_file( win32k.sys )
8252dda8     0    324     0     0     0     0  mapped_file( ShellIconCache )
8272f638   128    112     0   116     0     0  mapped_file( advapi32.dll )
......
82755958     0      4     0     0     0     0  mapped_file( $Directory )
8250b518     0      4     0     0     0     0    No Name for File
8254d8d8     0      4     0     0     0     0  mapped_file( $Directory )
82537be8     0      4     0     0     0     0  mapped_file( Windows Explorer.lnk )

--------  1348      0     0 ----- -----   904  process ( System )
--------   492      0     0 ----- -----    72  process ( winmine.exe )
--------  3364   1384  1396 ----- -----   188  process ( explorer.exe )
--------   972      0     0 ----- -----    88  process ( services.exe )
--------   496   1456   384 ----- -----   164  process ( winmgmt.exe )
--------  1144      0     0 ----- -----   120  process ( svchost.exe )
--------   944      0     0 ----- -----   156  process ( winlogon.exe )
--------   412      0     0 ----- -----    64  process ( csrss.exe )
......
--------    12      0     0 ----- -----     8  process ( wmiadap.exe )

--------   316      0     0 ----- -----     0  pagefile section (346e)
--------  4096      0     0 ----- -----     0  pagefile section (9ad)

--------   884    280    36 -----     0 -----  driver ( ntoskrnl.exe )
--------    88      8     0 -----     0 -----  driver ( hal.dll )
--------     8      0     0 -----     0 -----  driver ( kdcom.dll )
--------    12      0     0 -----     0 -----  driver ( BOOTVID.dll )
......
--------     8      0     0 -----     0 -----  driver ( ndisuio.sys )
--------    16      0     0 -----     0 -----  driver ( dump_scsiport.sys )
--------    56      0     0 -----     0 -----  driver ( dump_aic78xx.sys )
--------  2756   1060   876 -----     0 -----  driver ( Paged Pool )
--------  1936    128   148 -----     0 -----  driver ( Kernel Stacks )
--------     0      0     0 -----     0 -----  driver ( NonPaged Pool )</code></pre>
<p>The first column displays the address of the control area structure that describes each mapped structure. Use the <a href="#Bookmark2303"><b>!ca</b></a> extension command to display these control areas.</p>
<h2>Remarks</h2>
<p>You can use the <a href="#Bookmark2462"><b>!vm</b></a> extension command to analyze virtual memory use. This extension is typically more useful than <b>!memusage</b>. For more information about memory management, see <i>Microsoft Windows Internals</i>, by Mark Russinovich and David Solomon. (This book may not be available in some languages 

and countries.)
</p>
<p>The <a href="#Bookmark2399"><b>!pfn</b></a> extension command can be used to display a particular page frame entry in the PFN database.</p></div></div>	
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